This invention relates to the use of hydrogen peroxide in disinfection regimens, especially for devices or articles employed in medical applications, and to a means for dissipating residual hydrogen peroxide which may be present on or absorbed in the treated substance or items after disinfection is completed. More particularly, this invention deals with the use of sodium pyruvate to neutralize residual hydrogen peroxide on surfaces or remaining with articles and devices which have been disinfected through contact with dilute aqueous solutions of hydrogen peroxide or hydrogen peroxide producing compositions.
The effectiveness of hydrogen peroxide as a general disinfectant and its use as a germicidal agent in disinfecting a broad range of articles and devices employed in medical applications is well known. Plastic nebulizers, contact lenses, dental appliances, catheters and syringes are but a few of such articles. However, where a residual amount of hydrogen peroxide remains with such articles after treatment, the application of that article to living tissue may cause cellular damage or, at the very least, a significant amount of irritation to the patient. This is particularly true where the disinfected items are particularly or entirely made from materials that may absorb the hydrogen peroxide solution. Soft contact lenses are an important case in point because the very property which allows them to become soft by absorbing up to 150% by weight of water also permits substances which might otherwise be used for cleaning and or sterilization to be absorbed and even concentrated in the lens. When the contact lens is then placed on the eye such substances may be released to irritate and/or harm the sensitive tissues of the conjunctivae or cornea.
In the past when hydrogen peroxide has been utilized in disinfection regimens, various means have been proposed for the neutralization or dissipation of residual hydrogen peroxide. Of course, the simplest but least convenient and perhaps most time consuming method is to simply allow the treated surface to air dry. Another method has been to rinse the treated surfaces with an alkaline solution since hydrogen peroxide is less stable in such an environment. It is also well known that copious rinsing with water or a salt solution will dilute any residual hydrogen peroxide, but as suggested above this approach does not work satisfactorily with plastic components such as a soft contact lens which can absorb the hydrogen peroxide into its matrix. Attempts to dissipate residual hydrogen peroxide from the matrix of such contact lenses have included the incorporation of catalase or peroxidase in the rinsing/storage fluid, but enzymes are proteins which tend to adsorb to the surface being treated, thus diminishing the optical suitability of the lens. A more recent approach to removing residual hydrogen peroxide from contact lenses has been the incorporation of a platinum catalyst in a storage solution after the disinfection step, e.g., see U.S. Pat. No. 3,912,451. Unfortunately, the solid catalyst has a finite useful life and has to be replaced periodically. Furthermore, such catalysts yield undesirable ions into the lens storage solution and these, e.g., ions such as platinum ions, can have an adverse affect on normal corneal physiology.
The present invention represents a significant and unique departure for such concepts and, in a process for sterilizing surfaces and articles or devices with hydrogen peroxide, provides a convenient means for decomposing and removing any residual hydrogen peroxide remaining thereafter with such objects.